Automatic electrodynamic blowoff breaker with stationary contact form of two series wound u-shaped members

ABSTRACT

An automatic breaker, each pole of which comprises a movable and stationary system of contacts, characterized in that the stationary contact system is constituted as a series-wound coil having at least one turn and serving as an electrodynamic current limiter. The coil is composed of a stationary and movable element, the movable element of the coil serving as a stationary contact.

I United States Patent ml 3,593,127

[72] Inventors Gennldy Fedosievlch Mitskevich H6] Reierenees Cited W P 193, UNITED STA rEs PA'l w'rs 3,2l8.4l8 l/l965 Dorfman et al 200/144 2 571 42s l2/l95l Marcoz 337/66 Vakovlevieh Guochin, Moskovslty pr.. 96, I

232L594 l/l958 Latour 335/195 itv. 3|, vllttor lzralkvlch Rakhlis 3 092 699 6 '9 I i V '95 Moskovsky pr., :28. ltv. 54.; vim: A Itevolrloviclt Olttylbm. Mosltovsky pun, FOREIGN PA rENTS 96, ltv. 143; Jury Nikolaevich Vorontsov, 424,91 5/1967 Switzerland .i v 335/ l95 ulitsa Prospelttnayl, 28; 0k: lvanovidt 534,048 l2/l 954 Belgium 335/147 Artsybashev,l(orslltovslty per., 73; Fedor l.259,l l8 3/l96l France .i 335/16 Andreevlch Valthomchlk, ulitsl l,343,823 10/1963 France 335/ I6 Motomya, 5-5, ltv. 3., I of Kharkov, 46,194 I960 Poland H 335/16 [2H A I No Primary Examinr-Robert K. Schaei'er [22 1 52 28 1968 Assistant ExaminerRohert A. Vanderhye [4s] Pacmcd I, l3, Attorney Waters Rodin, Schwartz 8t Nissen I54] AUTOMATIC ELECTRODYNAMIC BLOWOFF BREAKER WITH STATIONARY CONTACT FORM as? SHAPED MEMEERS ABSTRACT: An automatic breaker, each pole of which comprises a movable and stationary system of contacts, characl Cl u 335/ I6, terized in that the stationary contact system is constituted as a 200/ I47, 335/147, 335/ I95 series-wound coil having at least one tum and serving as an [5| 1 Int. Cl "0th 77/10 electrodynamic current limiter. The coil'is'oomposed of a sta- [50] Field of Search i. 335/16, tionary and movable element, the movable element of the coil serving as a stationary contact.

PATENTED JUL 1 3 I8?! SHEET 2 BF 2 AUTOMATIC ELECTRODYNAMIC BLOWOFF BREAKER WITH STATIONARY CONTACT FORM OF TWO SERIES WOUND U-SI'IAIEI) MEMBERS The present invention relates to automatic breakers of high switching capacity, designed to protect electrical units against short circuit currents and overloads, as well as intended for operational switchings of AC and DC circuits.

Known in the art are automatic breakers, for instance, triple-pole breakers, wherein each pole has movable and stationary systems of contacts provided with arcing horns below arcing suppressors, as well as a controlling mechanism and a maximum current release gear (cf., Apparatus of low voltage distributors" by R. S. Kuznetsov, p. 198, Gosenergoizdat, 1962).

Breakers similar to the above-mentioned breakers are usually of low switching capacity.

Also known are automatic breakers of high switching capacity combined in one unit with quick-action fuses. These automatic breakers are inconvenient in use, since burned-out fuses are subject to replacement, thus leading to time waste, and the impossibility of remote control of said breaker. Also the provision of a fuse unit cannot but increase its overall dimensions.

It is an object of the present invention to provide a quick-action small-size automatic breaker with a high switching capacity and dependable restriction of short circuit currents, permitting remote control and convenient in use.

According to these and other objects, in an automatic breaker, each pole of which has movable and stationary systems of contacts, according to the invention, the system of the stationary contact is fashioned as at least a double-wound series coil serving as an electrodynamic current limiter and consisting of stationary and movable parts, the movable part of the coil functioning as a stationary contact.

The movable part of the series coil may have an elongated end serving as an arcing horn of the stationary contact.

Other objects and advantages of the present invention will be more apparent from the concrete description of an exemplary embodiment thereof and the appended drawings, wherein:

FIG. 1 is a general view of the automatic breaker, according to the invention; and

FIG. 2 (a, b, c, and 4) shows the positioning of the contacts of the automatic breaker, according to the invention.

Provided in a plastic body 1 (FIG. I) of the automatic breaker are movable and stationary systems of contacts, 2 and 3 respectively, an automatic breaker controlling mechanism 4, a maximum current release gear 5 intended for switching off the automatic breaker in case of emergency duty of a circuit protected.

The contact systems 2 and 3 are provided in each pole of the automatic breaker under an arcing suppressor made of steel plates 6 fastened on insulation walls 7, and a flame-extinguishing grid 8.

The stationary contact system 3 is fashioned as a double wound coil serving as an electrodynamic current limiter, and includes stationary and movable parts, 9 and I0 respectively.

A working contact II is fastened on the movable part 10 having an elongated end 12 serving as an arcing horn.

The movable and stationary parts 10 and 9 respectively, of the series coil are interconnected by means of an axle l3 and a currentcondueting flexible coupling 14 insuring the current flow from one part of the series coil to the other, unimpeding the turn ofthe movable part I0 about the axle I3.

For connection of the movable and stationary parts of the coil, a current-conducting hinge may be provided.

One end of the stationary part 9 of the coil has an aperture 15 for connection of exterior conductors of the main circuit.

The flexible part I0 of the coil is fitted with a spring 16 in suring the contact pressure, with the automatic breaker contacts being closed.

The movable system 2 of the contacts of each pole of the breaker comprises a contact 17 and a contact holder 18 connectable, by means of a flexible coupling I9, with a leadout bus bar 20.

The contact holder 18 has an arcing horn 21.

The contact holder 18 of each pole of the breaker is connected, by means of the controlling mechanism 4, with a handle 22 designed for manual control of the automatic breaker.

In order to actuate the automatic breaker, the handle 22 is transferred into the position A; as a result, the controlling mechanism 4 speedily rapidly shifts the contact holders l8 and instantly closes the contacts I] and I7 (FIG. 2a), said closure being independent of the speed of travel of the handle 22.

A closed electric circuit is thus formed.

The flow of the current through the series coil along a pointer D (FIG. 20) results in the emergence of electrodynamic forces tending to turn the movable part I0 of the series coil, on which the working contact 11 is provided, in the direction shown by pointer F.

However, the electrodynamic circuit induced by the series coil as well as the strain of the spring 16 are selected to be such that the turn of the movable part 15 occurs only after the current reaches a certain magnitude, i.e. the current of electrodynamic setting.

This same spring 16 produces the contact pressure, the contacts 11 and 17 being closed.

When a short circuit current stronger than the current of the electrodynamic setting of the series coil is induced in a protected circuit under the action of the electrodynamic forces emerging in said coil, the movable part 10 of the series coil begins to turn about the axle l3 breaking the contacts 11 and I7 (FIG. 21)) before the operation of the controlling mechanism 4. An electric are induced restricts the growth of the short circuit current, thus preventing it from reaching its maximum.

when travelling along the horns l9 and 21 (FIGS. 2b and 2c), the arc, apart from restricting the short circuit current, forms an additional coil, largely increasing the electrodynamic effect, which leads to a higher speed of breaking the contacts.

The arc travelling along the arcing horns I2 and 21, passes into an arching suppressor wherein it is dissipated and deionized by means of plates 6 (FIG, I). The flame and incan descent gases caused by the are burning pass into the flameextinguishing grid 8 wherein they are intensively cooled.

The provision of the flame-extinguishing grids 8 largely restricts the ionized gases beyond the arc-suppressing chambers, which is of primary importance for reducing the dimensions of the distributing devices.

Simultaneously with the turn of the movable part I0 of the series coil, the maximum current release gear 5 becomes operable, actuating the controlling mechanism 4 having a limited time of operation, which in turn withdraws the contact holder I8 keeping it in a withdrawn position insuring preset intervals for the contacts I1 and 17 (FIG. 2d).

The handle 22 occupies the position B (FIG. 1).

In the course of the operation of the controlling mechanism 4, the movable part I0 of the coil remains in a turned position (FIG. 2c) as long as the electric arc exists, as a result of the current flow through said coil. After the suppression of the arc, the movable part ll) of the series coil returns to the initial position under the action of the spring I6. The contact holders [8 are in the withdrawn position (FIG. 74).

In case an emergency current weaker than the current of electrodynamic setting of the series coil is induced in a circuit protected by the automatic breaker, and the maximum current release gear 5 become operable. The movable part II] of the series coil functions in this case as a stationary contact. The remaining process of automatic breaking is similar to that described hereinabove.

The position of the handle 22 (FIG. 1) indicates the switching position of the automatic breaker.

In the ON-position of the breaker, the handle 22 occupies the position A; if said breaker is switched off manually, the

handle is in the position C, and in case of an automatic disconnection, it is in the position 8.

in order to actuate the automatic breaker after automatic disconnection, it is necessary to first withdraw the handle 22 to the position C so as to wind up the controlling mechanism 4, and then transfer it to the position A.

Thus, the proposed automatic breaker is quick-acting, has small dimensions and insures reliable protection against overloads and short circuits of powerful electric circuits (grids) with strong short circuit currents.

Said breaker permits both manual and remote control since it does not require any change of parts after switching off short circuit current grids, as is the case with similar breakers provided with fuses; after switching off it is always ready for repeated operation.

All this largely expands the sphere of application of the automatic breakers described hereinabove.

We claim:

I. An automatic breaker comprising movable contact means, and stationary contact means, said stationary contact means comprising a stationary member, and a movable member, said movable member and said stationary member each being substantially U-shaped, said movable member and said stationary member each including an end portion pivotally connected to one another about a fixed axis such that said movable member is pivotally dispiaceable about the fixed axis relative to said stationary member and to constitute said stationary contact means as a continuous series wound coil.

2. An automatic breaker as claimed in claim I, wherein the movable member of the series coil includes an elongated end portion constituting an arcing horn of the stationary contact means.

3. An automatic breaker as claimed in claim I including resilient means interposed between said movable and stationary members.

4. An automatic breaker as claimed in claim 1 including a contact element connected to said movable member, said movable contact means including a contact element adapted for contacting said contact element of said movable member.

5. An automatic breaker as claimed in claim 2 wherein said movable contact means includes an elongated end portion constituting an arcing horn for cooperation with said arcing horn of said stationary contact means.

6. An automatic breaker as claimed in claim I including a lever connected to said movable contact means and adapted for permitting a manual displacement of said movable contact means.

7. An automatic breaker as claimed in claim 1 including arcing suppressor means and a flame-extinguishing grid connected proximate said movable and stationary contact means.

8. An automatic breaker as claimed in claim 7 wherein said arcing suppressor means includes a series of steel plates spaced from one another.

9. An automatic breaker as claimed in claim 1 including a bus bar, and a flexible coupling interconnecting said movable contact means with said bus bar. 

1. An automatic breaker comprising movable contact means, and stationary contact means, said stationary contact means comprising a stationary member, and a movable member, said movable member and said stationary member each being substantially U-shaped, said movable member and said stationary member each including an end portion pivotally connected to one another about a fixed axis such that said movable member is pivotally displaceable about the fixed axis relative to said stationary member and to constitute said stationary contact means as a continuous series wound coil.
 2. An automatic breaker as claimed in claim 1, wherein the movable member of the series coil includes an elongated end portion constituting an arcing horn of the stationary contact means.
 3. An automatic breaker as claimed in claim 1 including resilient means interposed between said movable and stationary members.
 4. An automatic breaker as claimed in claim 1 including a contact element connected to said movable member, said movable contact means including a contact element adapted for contacting said contact element of said movable member.
 5. An automatic breaker as claimed in claim 2 wherein said movable contact means includes an elongated end portion constituting an arcing horn for cooperation with said arcing horn of said stationary contact means.
 6. An automatic breaker as claimed in claIm 1 including a lever connected to said movable contact means and adapted for permitting a manual displacement of said movable contact means.
 7. An automatic breaker as claimed in claim 1 including arcing suppressor means and a flame-extinguishing grid connected proximate said movable and stationary contact means.
 8. An automatic breaker as claimed in claim 7 wherein said arcing suppressor means includes a series of steel plates spaced from one another.
 9. An automatic breaker as claimed in claim 1 including a bus bar, and a flexible coupling interconnecting said movable contact means with said bus bar. 